AT A KETAMINE TURNING POINT: Left or Right?
“Special K”
The use of Ketamine by the military in the prehospital environment traces back to the Vietnam war. Originally, Ketamine was cleared for civilian use in the United States as “Ketalar” at the beginning of 1970. At that time, it was valued as a possible “monoanesthetic” drug, capable of delivering analgesia, amnesia, loss of consciousness, and immobility in a single agent (1). Pretty amazing indeed.
The problem was that the drug also had the potential for side effects, such as hallucinations and psychotomimetic reactions. These side effects, in combination with the development of other IV anesthetics, contributed to its diminished role outside of the battlefield. Ketamine still conserved a unique feature amongst drugs of the same class though: a sympathomimetic effect that makes it the perfect (and only?) viable choice when it comes to hemodynamically unstable patients. That is right, sympathomimetic as in sympathetic, not only it will not decrease patient’s blood pressure and respiration, but there is a chance that Ketamine will increase blood pressure.
It sounds perfect, doesn’t it? Combine that with the fact that an overdose is nearly impossible; you now understand why medics from all over the world, conventional and special operations alike, are routinely administering Ketamine as a first line drug when it comes to trauma. Though hallucinations and psychotomimetic reactions are still part of the deal, anybody who has used Ketamine on their patients probably has some stories about it. Dealing with a combative trauma patient in the “field” is at the bottom of any medic’s wish list. The problem of combative patients has been overcome through the years by combining low dosage of benzodiazepines to the administration of Ketamine. But benzodiazepines, such as Midazolam might depress respiration in hypovolemic patients, right? And here we are again, right where we started. Don’t get me wrong, Ketamine does the job (actually jobs) like no other drug, but we are still striving for perfection and improvement. What if somebody invented a better Ketamine? One with half the downs and double the ups? Well, somebody did, and it is closer than you would think.
A little bit of history
The research that led to the discovery of Ketamine roots back to 1956 (2). A pharmaceutical company by the name of Parke-Davis started working on a compound called phencyclidine with the goal of creating an anesthetic agent with analgesic properties. Six years and many chemical compounds later, the union of a ketone and an amine resulted in a “compound with cataleptic, analgesic and anesthetic action but without hypnotic properties” (Mion, 2017, p.572). In just one word, Ketamine. Clinical trials quickly cleared the drug for veterinary use in Europe and shortly after it became available for human use in both the United States and most western European countries in 1970.